Yesterday I bought a pair of RCA Tall 5U4GB rectifiers on ebay. My question is....what is the difference between the usual short bottle version of this and the tall. The same seller had both priced about the same. I was thinking the tall version might be older or closer to the internal construction of the ST/Coke bottle version. Mark.

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare

I can't say that this is true in all examples of each type, but in my experience the taller will have a bit more extended seeming treble and a drier bass, a different texture to the sound. Sort of the way that a Decware amp sounds in comparison to a vintage amp. Now that can sometimes be too much of a good thing, and in some instances the shorter can really work well in a Decware amp. I'd say if you're looking for more bass and a darker, thicker presentation Mark the shorter may give you that in the Torii.

Lon, I was thinking I'd buy both sizes and compare but then decided I'd try the tall first since they don't come up as often. They were cheap....23 bucks shipped for a NOS testing pair and the short bottles were about the same. I'm sure both types will do better than the 5Y3GTs in my Torii currently. Once the HR-1s are in place I'll be better able to judge what I need to get the sound I want. I'll probably end up with the more expensive ST/Coke bottle versions before I'm done. Mark.

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare

Lon, I was thinking I'd buy both sizes and compare but then decided I'd try the tall first since they don't come up as often. They were cheap....23 bucks shipped for a NOS testing pair and the short bottles were about the same. I'm sure both types will do better than the 5Y3GTs in my Torii currently. Once the HR-1s are in place I'll be better able to judge what I need to get the sound I want. I'll probably end up with the more expensive ST/Coke bottle versions before I'm done. Mark.

I don't have any experience w/ the tall version, but I do have the short ones and I'd would agree w/ Lon's description. In my case, too much bass w/ my dm945s and bass cabinets. Bass was boomy and loose. Had to go w/ the RCA 5Y3GTs which gave me a nice tight and accurate sounding bass. With the right speakers tho, I'm sure the 5U4GBs would be great.

My experience with RCAs is the same. The short bottle is denser and darker, and the tall, bigger, more balanced and neutral. But both are pretty different than 5Y3GTs and also STs. I used STs first, then had a fling with GBs, and then back to STs.

Mark, as Greg suggests, if the balance of bass is good with 5Y3GTs you will very likely get notably more and deeper with both GB's, but the taller will likely have a more open midrange. This could be good or bad depending on tastes and system.

James is talking about another real option if the GB range generally suits you. For an even more big bottle sound, with a bit more body in the mids, but also a more spacious feeling, more ambient information, there is an RCA (sometimes labelled other companies) that has no bottom mica and the internals are like STs, but they too sound different than STs. Like these: http://www.ebay.com/itm/2-x-5u4gb-RCA-Rectifier-Tubes-Tall-Bottle-Black-Plates-3...

In fact, all my pairs of STs sound at least a little different.

I have found relatively inexpensive STs if your interest takes you there. You have to watch on Ebay, and look very closely at the construction to be sure that they not only match in tests, but also in construction...the getters shape and location, the plate shape and width, ribs or not, and the actual bottle shape and how the micas fit in the bottle. Also, they may be labelled something else. I got some really nice, true NOS Raytheon labelled RCAs for about 60 delivered....sort of like two pair of GBs.

I like them all and it depends a lot on what you have them with. Since you are coming from the 5Y3GT, I am thinking the best thing to do might be to find out if your preferences take you into the GBs over the 5Y3GT with that first tall bottle pair you bought, and go from there.

Thanks everyone for the great info. I'll refer back here once I've got my HR-1s burned in. Unfortunately I don't think I'll get them until maybe the end of March. I've been waiting to see what speakers Bob would start building next. My question was answered this morning...he has begun two pair of ERRs. Sigh. Mark.

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare